Process of making hydrogen.



, No Drawing.

onrrnp STATES PATENT orrroa.

RAOUL PIERRE PICTET, F WILMERSDORF, NEAR BERLIN, GERMANY. I

PROCESS OF MAKING HYDROGEN.

To all whom it may concern.

Be it known that 1, Recon PIERRE P'Ic'rE'r, a citizen of the SwissRepublic, residing at Uhlandstrasse 116, Wilmersdorf, near Berlin,Germany, have invented certain new and useful Improvements in Processesof 0 Making Hydrogen, and I do hereby declare the following to be afull, clear, and exact description of the invention. p

The subject-matter of my invention is an improved process of makinghydrogen.

At the present day large quantities of hydrogen are required as, forexample, for airships, metallurgical operations and so on. It iswell-known that when petroleum and coal-tar oils are heated they producea soot-like smoke and very complicated, gaseous products both of theparafiin series, such as methane, ethane, propane, and of the olefinseries, such as ethylene and so on.

Now a primary object of this invention is to provide a process of'makingfrom the crude petroleum of commerce, lubricating oils, solar oils,paraffin oils or gasolene, gases suitable in each instance to theirpurpose ofemployment.

As compared with known modes of manufacture, my process has the greatadvantage that it is cheap and can be readily carried into practice. Myprocess substantially consists in liquid petroleum, for example, beingvaporized alone or-mixed with water,' a suitable quantity of oxygenbeing added, if preferred, to the mixture of hydrocarbon and steam. Thepetroleum may, of course,

. be vaporized by itself and the steam, possibly mixed with oxygen, besupplied to the pipe in which decomposition of the introduced materialsis to take place, or the desired gases or mixtures of gases are to beformed. Further, the petroleum may be vaporized alone and the wateralone and united shortly before the pipe with the oxygen vuhich ispossibly to be supplied. Obviously, the present process can be varied inmanifold ways in this direction. v

The boiler or tank may be heated with any fuel, 6. 9. coal, gas and soon. The petroleum and the water or the petroleum alone is preferablyboiled at atmospheric pressure. The vapors are conducted through; along, e. 9. horizontal, iron pipe which is heated along its entirelength to a temperature approximating the melting point of iron. This isessential.' The length of the Specification of Letters Patent.

Patented Apr. a, fera Application filed May 29, 1911. Serial No.630,177.

pipe will depend in each instance on the gas or gaseous mixture which itis wished to obtain. The temperature of the. vapors in the pipegradually .rises until it reaches that of the pipe. The vapors passhence into a water-cooled receiver and, if desired, the gaseous productscan here be separated from the other products, in so far as pm,- visionhas not been made, say, by supplying steam, or steamand oxygen, forpossibly completelybonverting the solid constituents into gas or gaseousmixtures, and after having been filtered they pass into a gasometer.

My process maybe carriedinto practice, for example, by supplying steamto the liquid petroleum at any suitable place; this will be done when itis wished to obtain hydrogen containing carbon monoxid. If, on thecontrary, it is wished to obtain hydrogen free from carbon monoxid,petroleum alone or mixed'with other hydrocarbons will be employed, orsteam mixed with oxygen will be employed, this being done when it iswished to obtain complete conversion.

In order that the conditions to be observed in carrying my process intopractice may be clearly understood, the followii'i g general particularswill serve.

In the eventof only petroleum belng employed without using Water, thefollowing can be observed: When petroleum vapors are gradually heated inthe iron pipe from about 200 (J. to about 1200 0., during the heating ofthe gases three modifications can be determined. This determination canbe made by removing tests of gas from small holes drilled in the pipe.At "first vapors having a brown color with the characteristic odor ofthe vapors produced from heavy oils is'obtained; when these vapors arecondensed in-the test tubes they have a slight violet color. Secondlythe brown color of the vapors changes to green; on condensation in testtubes a dark brown oil is obtained. Thirdly, when vapors are removed atthe highest temperature at the end of the which is preferably an ironorsteel Pipe it is found that they have become black and that aftertheyhave been condensed in.

lee

per liter of gas after-filtration constantly diminishes corresponding tothe rise in temperature of the gases. Toward'the end of the pipe the gashas a specific'weight 0.55

to-0.25 and a buoyancy 0.75 gr. to 1 gr. per

liter (in caoutchouc balloon). When these three holes bored in theheated tube are placed closer together, it is found that the gases inthe pipe at about 800 C. to 1200 C. consist of carbon and of puremethane in combination with a certain quantity of pure hydrogen. Up to atemperature of approximately over 1200 C. the quantity of 'pure hydrogenconstantly increases, while the percentage of'methane decreases and ofcarbon dust increases. On the other hand,

it has been found that for each gram of methane to be dissociated atover 1200 to 1350 0., 18.1 calories must be supplied through the wallsof the pipe, 0. 9. an iron pipe, to the gas. Thisv quantity of heatshould be supplied to the gas through a pipe wall which is itself heatedto near the would melt.

melting) point of iron, that is to say not over methan into itsconstituent elements re-.

quire very large areas which apparently would -not be in the correctproportion to the surface'of the pipe whose influence at the start hasbeen considerable, because the gases circulating in the pipe were stillat a low temperature. This experimental confirmation forms thefoundation of the present process, for it is seen that the constructionof the apparatus must meet very special, essential conditions. I

Petroleum or any liquid hydrocarbon of exothermic constitution isemployed, and consequently not acetylene. The petroleum is vaporized andthe vapors are led into a heated pipe, whereby a series of chemicalmodifications of these vapors are produced, until they have been reducedto the mixture of three bodies orclasses of bodies, namely methane,various vapors of coal-tar oils, and

soot. The temperature then approximates to 1200 to 1350 (3.; at thisplace the sur-"v face of the heated pipe must have a sufli-.

cient extent in order that 18.1 calories per 16 gra ns of gas can besupplied to the gases passing throughthe pipes at this high temperature.The temperature of the pipe may not attain 1350" 0., z'. e. it mustremain below the melting point of iron. This condition, which isdiflicult to fulfil-in practice, has rendered the known distillationprocess for hydrocarbon'diflicult.

' Of course it. is possible to carry my processinto practice in manyvarious ways. The soot produced can be removed continuously orintermittently. l For the case when. petroleum is vaporized tails willserve: In the above described example 1 kg. petroleum results in about 700 g.

soot, about 200 g. pure hydrogen and about. I

.u )0 got heavy vapors of hydrocarbons which are not decomposed at thetemperature near 70.. at the same time as water the following dethemelting point of iron. 700 g. carbon 3 I heated with 933 g. pureoxyen'produce, as is well-known, pure' carbon monoxid.- Now when 1050 g.water are decomposed 933 g.

oxygen and 117 g. hydrogen are produced,

as is known. Inorder to obtain complete decomposition 68.36 caloriesmust 'be supplied to each molecule of water. Each molecule of carbonmonoxid supplies, however,

during its formation 29 calories. Now for converting 933 g. oxygen into1603-g. carbon monoxid 2294 calories must be supplied through the wallvof the iron'pipe, it being understood that these numbers hold good when1 kg. petroleum and 1050 g. water are to be vaporized. This 'quantityofheat, namely 2294 calories, for the present ex ample, must be su pliedto the wall of the iron pipe besides t e quantity of heat requisite forconverting petroleum vapors into carbon and methane, or methane intocarbon and hydrogen. v

The pipe which'is employed, e. g. an iron pipe, must of coursebelengthened c'orre-' spondingly, i; e. in proportion to the increase ofthe additional quantity of heat supplied. If it-were wished to supplythe quantity of heat (2294 calories) to the wall of the pipe byproviding a more intense furnace,the aim in View could not-be attainedbecause the pipe .would be ,melted. Consequently, the present processcan be suitably carried into practice only by provision being made,

as mentioned .above,-for the pipe in which the hydrogen and carbonmonoxid are converted being suitably lengthened.

. In the described apparatus amaximum of 2220 liters of pure hydroge and700 g.

soot which is moistened sayswith 100g. nondecomposed fatty oil c'anb'eobtained.

My process 1s carried into practice, for

example, as follows :-1 kg. petroleum. and

1050 g. water are allowed to flow simultaneously into a boiler; Thesetwo substances ably iron pipe heated almost to thef melting point ofiron. The following maximum.

quantities ofjsubstances will be obtained: By the decomposition of themethane 2220 1. pure hydrogen, by the decomposition of the steam 1300"1. pure hydrogen, by the combustion of 700 carbon, 1633' g. carbonmonoxid and a re'si ue of 100 gQnon-decoxiipoSd' 'coal-tar oils, These1633 g. carbon are then vaporized andpassed into a prefermamas a.

monoxid occupy a volume of'1307 l. The total volume of the gaseousmixture finally obtained consisting of hydrogen and carbon monoxid andresulting from 1 kg. petroleum will be 4827 1., composed of 3520 1.hydrogen and 1307 carbon monoxid calculated at 0 C. and 760 m/m. Thebuoyancy of this mixture of gases is 0.887 g. per liter and the specificweight 0.406. The heat of combustion of this mixture of gases is 3022calories per cubic meter.

' be more or less complete according in each instance to the quantity ofwater supplied. The more rich the final gas is in carbon monoxid, themore soot must enter into the reaction. 1

' For more clearly explaining this form of my invention the followingdetails will serve The gaseous mixture produced by the simultaneousdistillation of hydrocarbon vapors and steam, and specially adapted foruse for industrial purposes, as e. g. for autogenous welding and thelike and as a substitute for benzin, spirit and the like, has acalorific capacity of combustion of about 3000 calories per cb. m. Nowit has been found that complete conversion at the temperature-near themelting point of iron does not take place because, on the one hand, the

temperature of decomposition of the steam (under the-influence of thefinely divided carbon) is higher than .that of the hydrocarbons and,on'the other hand, a deficit of 30.calories is obtained owing to thequantity 'of heat absorbed byeach molecule of water for each 18 g. waterwhich entered in the form of steam into the pipe. If, on the contrary,it is wished to obtain complete conversion, steam mixed with oxygen willpreferably be supplied to the hydrocarbon vapors.

N ow' it has been observed that at about 1300 C. 20-25 of the suppliedwater is converted into gas and mixeswith the pure hydrogen. Ifthetemperature approaches 1400 or- 1500 C. the relation increases twofoldor threefold, i. e. almost complete conversion of the water is obtained.The hydrocarbon vapors are supplied-with steam'mixed with any desiredquantity of oxygen, and the mixture of steam andoxygen should besupplied near the point atwhich the hydrocar-,

Icons enter. Th'e mixtureofsteam and oxy-. gen should be as regulatableas possible.

The following now takes place: Each mole-- cule of oxygen charged wlthsteam meets inthe heated pipe with hydrocarbon molecules which arealready decomposed and have formed carbon in statu nascemli. This veryhot-carbon in statu nascendz' is now able to convert the steam andoxygen when the necessary quantity of heat for this process; ofdecomposition is supplied to the same at this place at the moment whenthe carbon in statu nascemlz' is produced. As the carbon is present inexcess at this part of the pipe filled withchydrocarbon vapors, heat isdeveloped, the oxygen from the steam and the oxygen which is suppliedfrom carbon monoxid, each molecule of which supplies 29 calories. When asuitable quantity of oxygen is supplied to the steam, all the carbon canbe bound which has been formed by the decomposition of the hydrocarbonwithout having to change the temperature of the chamber in the pipe. Thequantity of heat consumed by the decomposition of the water is marriedtarily covered by the quantity of heat produced in the formation of thecarbon monoxid which is added to the generated hydrogen. Y

Owing to a certain quantity of oxygen mixed with steam being brought in,the 1 heat of decomposition of the hydrocarbon and of the hydrogen canbe completely covered. To bring about this double covering,

it suflices exactly to regulate the ratio of the L hydrocarbon vaporscontinuously flowing through the pipe to the mixture of. steam andoxygen.

When carrying my process into, practice the pipe is heated to atemperature at which the hydrocarbon vapors are From this temperaturedownward (about 1350 C.) the fire surrounding the pipe h'asmerely thepurpose of raising the temperadecomposed.

ture of the vapors flowing into the pipe at their normal temperature to1350 C. It is not necessa to supply fresh quantities of I heat tothewall of the heated pipe. As all chemical reactions taking place in" thepipemutuall bring about a state of thermic equilibrium, the externaltemperature of the wall of the pipe will be lower than was pre-" viouslythe case as long as the absorbed heat is substituted by exteriorheating. 7 Gonse-f quently, the pipe is-no longer exposed to beingmelted byv the heat. Thus a complete reaction with material shorteningof thepi-pe, .canbe obtained which is importantfor certain purposes.The-gas which is obtained is ami'xture of hydrogen and carbon monoxidwithout any material admixture of I1ltIfO-,.

gen oncar-bonic acid, traces of which n1 are present. It hasnotheretofore been possible to make this gaseous mixture ,by a continuousprocess.

' It is to be understood that the oxygen used for the described processmay be made ac cording any process, but oz r ygen, made from thedistillation of liquefied air is particularly suitable for the presentpurpose.

I claim l. The method of producing pure hydro- 7 gen from-exothermichydrocarbons such as ficient to dissociate the hydrocarbon into carbonand pure hydrogen and collecting the hydrogen.

2. The method of producing pure hydrogen from' exothermichydrocarbonssuch as described, which comprises supplying to one end of a conduit acontinuous current of hydrocarbon vapor while heating the conduit tonear the melting point of iron, there-- by dissociating thehydrocarboninto pure hydrogen and carbon, and discharging the purehydrogen in a continuous current from the other end of the conduit.

' 3. The method of producing pure, hydrogen from exothermic hydrocarbonssuch as described, which comprises passing a continuous current ofhydrocarbon vapor through a conduit heated from about 1200 C. to 1350 C.and supplying through the walls of the conduit 181 calories of heat toevery 16 gramsof gas, thereby dissociating the hydrocarbon into carbonand hydrogen,

and discharging the hydrogen continuously from said conduit.

,In testimony whereof I havesigned'my name to this specification, thepresence of.

two subscribing witnesses.

' RAOU'L PIERRE PICTET. v Witnesses? A HENRI LINN,

R. Wns'moo'nu-

